1. Field of the Invention
The present invention relates to a joy stick type operating lever device used in construction equipment such as hydraulic shovels, bulldozers, or cranes, or in ships.
2. Description of the Related Art
In general, in such construction equipment, there may be provided an operating lever which can be operated two dimensionally, for example, forward and backward, right and left, or vertically and horizontally, in the X or Y direction. In a so-called joy stick type operating lever in which each operating angle of the operating levers in the two dimensional direction is detected by a corresponding lever operating detecting means, various operation controls are carried out based on detection signal data from each of the lever operation angle detecting means. This requires the detection signal of each of the lever operation angle detecting means to be input to the main control section side. Detection signals have been conventionally input to the main control section using a total of at least four lines, two lines for outputting signals from each of the lever operation angle detection means, and a supply line and a ground line. This meant that an equal number of connectors as lines had to be provided at the main control section side.
In operating equipment such as hydraulic shovels, two joy stick type operating levers are usually used for operating the operation section. In addition, switches are often provided for the operating levers to arbitrarily execute a desired function. When inputting signal data from these switches to the main control section a total of five lines are required for one operating lever. These lines are, as shown in FIG. 6, the supply line +B, the ground wire GND, signal data wires SIG 1 and SIG 2 for the X direction lever operation angle detecting means 2 and the Y direction lever operation angle detecting means 3 respectively, and the wire SW 1 for the switches 6. This means that five pin connectors are required at the main control section side. When there are two operating levers, two sets of five pin connectors must be provided, which causes the wiring to become complicated and increases the number of parts used.
In order to overcome this problem, the power line and the ground line, which extend from each of the operating levers, have been connected to form a common line. However, a total of eight wires are still necessary because this decreases the number of wires only by two, so that this method does not really simplify the wiring. In recent years, various operations such as moving operations have been frequently carried out by means of control commands from the main control section, which have been generated based on the electrical detection of the operations with operation input detecting sensors or change-over switches. When operations are carried out in such a way, however, the number of wire connections to the main control section increases, which not only makes wiring troublesome and complicated, but also increases costs. In addition, the greater number of connector pins increases the occurrence of contact failure, which may affect the reliability of the lever device.